that I may place: Heb. שִׁתִי, lit., My placing, that I may place. — [after the targumim]

שתי: שימי שאשית אני:

2and in order that you tell into the ears of your son and your son's son how I made a mockery of the Egyptians, and [that you tell of] My signs that I placed in them, and you will know that I am the Lord."

I made a mockery: Heb. הִתְעַלַלְתִּי, I mocked, like “Because you mocked (הִתְעַלַלְתִּי) me” (Num. 22:29); “Will it not be just as He mocked (הִתְעַלֵל) them” (I Sam. 6:6), stated in regard to Egypt. It is not an expression meaning a “deed and acts (מַעִלָלִים),” however, for were that so, He would have written עוֹלַלְתִּי, like “and deal (וְעוֹלֵל) with them as You have dealt (עוֹלַלְתָּ) with me” (Lam. 1:22); “which has been dealt (עוֹלֵל) to me” (Lam. 1:12).

5And they will obscure the view of the earth, and no one will be able to see the earth, and they will eat the surviving remnant, which remains for you from the hail, and they will eat all your trees that grow out of the field.

and no one will be able: Heb. יוּכַל lit., and will not be able. The seer [will not be able] to see the earth, but [the text] speaks briefly.

ולא יוכל וגו': הרואה לראות את הארץ, ולשון קצרה דבר:

6And your houses and the houses of all your servants and the houses of all the Egyptians will be filled, which your fathers and your fathers' fathers did not see since the day they were on the earth until this day.' " [Therewith,] he turned and left Pharaoh.

just as I will let you… out: and surely I will not let the flocks and the cattle out as you said.

כאשר אשלח אתכם ואת טפכם: אף כי אשלח גם את הצאן ואת הבקר כאשר אמרתם:

See that evil is before your faces: [Understand this] as the Targum [Onkelos] renders it. I have [also] heard an Aggadic midrash, however [which explains the passage as follows]: There is a star named Ra’ah [i.e., רָעָה meaning evil]. Pharaoh said to them [Moses and Aaron], “With my astrology I see that star ascending toward you in the desert [where you would like to go], and that is a sign of blood and slaughter.” When the Israelites sinned with the calf, and the Holy One, blessed be He, sought to kill them, Moses said in his prayer, “Why should the Egyptians say, ‘With Ra’ah He took them out…?’” (Exod. 32:12) This is what he [Pharaoh] said to them, “See that Ra’ah [evil] is opposite your faces,” [implying that their blood would be shed in the desert]. Immediately, “The Lord repented of the Ra’ah [the sign of the star]” (Exod. 32:14), and He turned the bloodshed [symbolized by this star] into the blood of the circumcision, for Joshua [in fact] circumcised them. This is the meaning of what is said: “This day I have rolled away the reproach of the Egyptians from you” (Josh. 5:9), for they were saying to you, “We see blood over you in the desert.” -[from Midrash Shir Hashirim, Wertheimer 1:2]

Not so: as you have said [that you want] to take the young children with you, but let the men go and worship the Lord. — [from Jonathan]

לא כן: כאשר אמרתם להוליך הטף עמכם אלא לכו נא הגברים ועבדו את ה':

for that is what you request: ([meaning] that worship) you have requested until now, [telling me,] “Let us offer and sacrifice to our God” (Exod. 5:8), and young children do not usually offer up sacrifices. — [from Exod. Rabbah 13:5]